Seismic adapter

ABSTRACT

A seismic adapter for attachment to a steel web joist. The joist includes a pair of angled elements which extend parallel to one another with a cord space therebetween. The adapter includes an anchor plate juxtaposed with the upper surface of the element pair and an engagement plate engaging the parallel edges of the legs of the element pair. A threaded stud attaches to the anchor plate and extends through the engagement plate. The extension of the stud provides for the attachment to a hanger adapter brought together by a nut on the stud. The engagement plate includes a flat anchor portion and upstanding engagement portions having distal edges with interlocking engagement profiles including a tongue and outwardly extending shoulders to receive the parallel edges of the angle element pair.

CLAIM OF PRIORITY

This application is a continuation of U.S. patent application Ser. No.10/759,873, filed Jan. 16, 2004; which is a continuation of U.S. patentapplication Ser. No. 09/844,807, filed Apr. 27, 2001.

BACKGROUND OF THE INVENTION

The field of the present invention is building construction hardware formounting components such as utilities.

Building construction frequently uses steel web joists. Such devicesemploy two beams. The beams are mutually parallel and spaced apart tocreate a large moment of inertia for the joist. Cord elements extend atangles between the two so the beams will act as one in bending. Eachbeam includes a set of two elongate angle elements which are alsomutually parallel. The cord elements extend for anchoring to between theelongate angle elements which form a cord space to receive the elements.Each angle element includes two legs extending at a right angle to oneanother, a first leg which is parallel with the first leg of the otherangle element to define the cord space and a second leg extending in theopposite direction from the second leg of the other angle element togenerally define a plane. The two first legs extend to define paralleledges.

Seismic adapters have been associated with such steel web joists bypositioning two flat washers about one of the sets of angle elements.One washer lies in the plane of the second legs such that it extendsacross the cord space in juxtaposition with the second legs. A secondwasher is arranged to abut against the parallel edges of the first legs,also extending across the cord space. A threaded stud extends betweenthe washers with a nut or bolt head retaining the first washer injuxtaposition with the second legs. The threaded stud extends beyond thesecond washer to accommodate attachment hardware. The entire assembly isthen clamped to the joist by threading a nut up snug against theattachment hardware and, in turn, the second washer. Although thissystem is structurally sound, there is some prospect of limited lateralmovement of the attachment.

SUMMARY OF THE INVENTION

The present invention is directed to a seismic adapter for attachment toone beam of a steel web joist. An anchor plate having a holetherethrough is positionable across the cord space into juxtapositionwith the second legs of the beam. An engagement plate having a holetherethrough abuts up against the parallel edges of the first legs ofthe beam. A threaded stud extends from the anchor plate to and beyond ahole in the engagement plate. The engagement plate is able to interlockwith the first legs.

In a first separate aspect of the present invention, the engagementplate includes a flat anchor portion and upstanding engagement portionsto either side of the flat anchor portion. The engagement portions havedistal edges with an engagement profile for interlocking engagement withthe beam. This greatly restricts or eliminates any lateral movement ofthe adapter.

In a second separate aspect of the present invention, the engagementplate includes distal edges with tongues extendible to between theparallel legs of the steel web joist beam for interlocking engagement.The tongues may be tapered to accommodate variations in the cord space.Shoulders to either side of each tongue may abut against the edges ofthe legs.

Accordingly, it is an object of the present invention to provide animproved seismic adapter. Other and further objects and advantages willappear hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a seismic adapter placed within a beam of asteel web joist and mounting additional hardware thereto; the viewincluding end views of an anchor plate and an engagement plate.

FIG. 2 is a plan view of the anchor plate.

FIG. 3 is a side view of the engagement plate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning in detail to the Figures, one beam of a steel web joist isillustrated as including two angle elements 10 and 12. The angleelements each have a first leg 14 and a second leg 16. The first legs 14extend in parallel, spaced by a cord space 18 therebetween. The secondlegs 16 extend in opposite directions from one another, defining acommon plane.

The seismic adapter associated with the steel web joist includes ananchor plate 20 which provides plate means for anchoring by extendingacross the cord space of the steel web joists into juxtaposition withthe second legs 16. The anchor plate 20 is a square flat plate with acentrally formed threaded hole 22. The hole typically is sized toreceive a threaded half inch stud.

An engagement plate 24 includes a flat anchor portion 26 having a hole28 centrally extending therethrough. Upstanding engagement portions 30and 32 extend from either side of the flat anchor portion 26 to providemeans for interlocking engagement with the first legs 14 of the steelweb joist. The upstanding engagement portions 30 and 32 form obtuseangles substantially greater than 90° as illustrated in FIG. 3 with theflat anchor portion 26 with all being formed from the same plate. Thedistal edge of each of the upstanding engagement portions 30 and 32defines an engagement profile for interlocking engagement. Theengagement profile includes a tongue 34 which is tapered inwardly towardthe distal extent thereof. Each engagement profile on the distal edge ofthe upstanding engagement portions also includes shoulders 36 and 38 toeither side of the tongue 34. These shoulders 36 and 38 abut against thelower edges of the first legs 14 of the steel web joist. The shoulders36 and 38 extend further outwardly from the engagement portions thefurther they are from the tongue 34.

To draw the anchor plate 20 and the engagement plate 24 together, a stud40 is shown in threaded engagement with the threaded hole 22 of theanchor plate 20 in FIG. 1. The other end of the stud 40, which is shownin this embodiment to be threaded along its length, extends to andbeyond the hole 28 in the engagement plate 24. A nut 42 is threaded ontothe lower end of the threaded stud 40 to capture an attachment bracket44 employed for bracing piping 46 and the like.

In assembly, the stud 40 with the nut 42 in place is extended throughthe attachment 44 and the engagement plate 24. This assembly is thenpositioned with the stud 40 extending through the cord space between thelegs 14 of the beam of the steel web joist. The stud 40 is then threadedinto the anchor plate 20. The nut is next tightened to a torque minimumof 40 ft. lbs. Various adapters may be employed with this system and theorientation of the adapters can vary. The adapter is placed within sixinches of the attachment point of any cord element to the upper angleelement pair. The taper on the tongue 34 and the extensions of theshoulders 36 provide an interlocking effect to accommodate variations inthe cord space of the associated beam of the steel web joist.

Thus, an improved seismic adapter is disclosed. While embodiments andapplications of this invention have been shown and described, it wouldbe apparent to those skilled in the art that many more modifications arepossible without departing from the inventive concepts herein. Theinvention, therefore is not to be restricted except in the spirit of theappended claims.

1. A seismic suspension system for a web joist, comprising an anchorplate including a first hole therethrough; an engagement plate includinga flat anchor portion having a second hole therethrough and two flatupstanding engagement portions, one to either of two opposed sides ofthe flat anchor portion, each upstanding engagement portion being at anobtuse angle substantially greater than 900 to the flat anchor portionand having a distal edge with an engagement profile including twoshoulders with a tongue therebetween, the tongue and the shouldersdefining concavities therebetween; a stud extending from the first holeand threadably engaged therewith to and beyond the second hole with athreaded engagement beyond the second hole.
 2. The seismic suspensionsystem of claim 1, the tongue and the shoulders being tapered to definethe concavities as V-shaped concavities.
 3. The seismic suspensionsystem of claim 1 further comprising a nut threadably engaged with thestud at the threaded engagement.
 4. The seismic suspension system ofclaim 1, each engagement profile having a terminal edge substantiallyperpendicular to the flat upstanding engagement portion.
 5. A seismicsuspension system comprising the anchor plate, engagement plate and studof claim 1; a web joist including a beam with two angle elements, eachhaving a first leg and a second leg, the first legs being parallel witha cord space therebetween and the second legs extending in oppositedirections, the anchor plate extending across the cord in juxtapositionwith each second leg, the engagement plate being positioned with thefirst legs extending into the concavities and the stud extending throughthe cord space to engage the anchor plate and the engagement plate. 6.The seismic suspension system of claim 5 further comprising a nutthreadably engaged with the stud at the threaded engagement.
 7. Theseismic suspension system of claim 6 further comprising a bracketpositioned over the threaded engagement between the flat anchor portionand the nut.
 8. The seismic suspension system of claim 5, eachengagement profile having a terminal edge substantially perpendicular tothe flat upstanding engagement portion.
 9. The seismic suspension systemof claim 4, the tongue and the shoulders being tapered to define theconcavities as V-shaped concavities.